‘JG believed that even in a demanding industry, it was possible to lead with both rigor and humanity’

“If you are reading this, it means that I’m no longer around and lost my fight with cancer,” read a self-penned note on his LinkedIn account. “This note is just a massive thank you to all of you. Thank you for the fun, for sharing the struggle, for helping me learn along the way, and being a group of quality people that enriched my life. I wish you all the very best in the years to come!”

“JG meant so much to so many of us at OpenX, and our thoughts and deepest sympathies are with his family and friends during this difficult time,” read an official note from OpenX, which went on to conclude, “JG believed that even in a demanding industry, it was possible to lead with both rigor and humanity. We will carry that forward.”

Gentry was one of the pioneering executives of ad tech, holding several roles at OpenX since 2012, culminating in a distinguished career that earlier saw him serve at startups, including Spot Runner and Green Dot, as well as at corporate entities such as Disney and Overture.

John led OpenX with a steady hand and an uncommon decency, and to know him was to know that he was one of the good guys. The outpouring of love for the man following his passing is a testament to that. In an industry riddled with egos and hidden agendas, John was someone who wanted to see others thrive. He made himself accessible at the trickiest moments and never treated people as stepping stones.

He believed that businesses grow when people feel trusted and respected, and he built a culture around that belief. Competitors admired him, colleagues relied on him, and younger executives sought him out because he listened more than he lectured.

The advertising world can be transactional and unforgiving. John proved it did not have to be that way. He showed that leadership can be ambitious without being ruthless, and strong without losing kindness.